Example of dataset Consider the case where a professor in physics department teaches an electric engineering course. Even though there is a valid entry in teaches, it is lost in the natural join of instructor, teaches and course, since the instructor’s department name does not match the department name of the course...

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Answer 1

Expert Solution & Answer

Chapter 4, Problem 5PE

a.

Explanation of Solution

Example of dataset

Consider the case where a professor in physics department teaches an electric engineering course.

Even though there is a valid entry in teaches, it is lost in the natural join of instructor, teaches and course, since the instructor’s department name does not match the department name of the course...

b.

Explanation of Solution

Reason for using query

The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

c.

Explanation of Solution

Reason for using query

In the query,

select * from teaches natural join instructor;

In the above query, some sections are lost if teaches...

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Answer 2

Expert Solution & Answer

Chapter 4, Problem 5PE

a.

Explanation of Solution

Example of dataset

Consider the case where a professor in physics department teaches an electric engineering course.

Even though there is a valid entry in teaches, it is lost in the natural join of instructor, teaches and course, since the instructor’s department name does not match the department name of the course...

b.

Explanation of Solution

Reason for using query

The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

c.

Explanation of Solution

Reason for using query

In the query,

select * from teaches natural join instructor;

In the above query, some sections are lost if teaches...

Expert Solution & Answer

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Check out a sample textbook solution

See solution

Answer 3

Expert Solution & Answer

Chapter 4, Problem 5PE

a.

Explanation of Solution

Example of dataset

Consider the case where a professor in physics department teaches an electric engineering course.

Even though there is a valid entry in teaches, it is lost in the natural join of instructor, teaches and course, since the instructor’s department name does not match the department name of the course...

b.

Explanation of Solution

Reason for using query

The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

c.

Explanation of Solution

Reason for using query

In the query,

select * from teaches natural join instructor;

In the above query, some sections are lost if teaches...

Expert Solution & Answer

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Check out a sample textbook solution

See solution

Answer 4

Expert Solution & Answer

Chapter 4, Problem 5PE

a.

Explanation of Solution

Example of dataset

Consider the case where a professor in physics department teaches an electric engineering course.

Even though there is a valid entry in teaches, it is lost in the natural join of instructor, teaches and course, since the instructor’s department name does not match the department name of the course...

b.

Explanation of Solution

Reason for using query

The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

c.

Explanation of Solution

Reason for using query

In the query,

select * from teaches natural join instructor;

In the above query, some sections are lost if teaches...

Expert Solution & Answer

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Check out a sample textbook solution

See solution

Answer 5

Expert Solution & Answer

Answer 6

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Answer 7

Chapter 4, Problem 5PE

a.

Explanation of Solution

Example of dataset

Consider the case where a professor in physics department teaches an electric engineering course.

Even though there is a valid entry in teaches, it is lost in the natural join of instructor, teaches and course, since the instructor’s department name does not match the department name of the course...

b.

Explanation of Solution

Reason for using query

The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

c.

Explanation of Solution

Reason for using query

In the query,

select * from teaches natural join instructor;

In the above query, some sections are lost if teaches...

Answer 8

Chapter 4, Problem 5PE

a.

Explanation of Solution

Example of dataset

Consider the case where a professor in physics department teaches an electric engineering course.

Even though there is a valid entry in teaches, it is lost in the natural join of instructor, teaches and course, since the instructor’s department name does not match the department name of the course...

Answer 9

Chapter 4, Problem 5PE

a.

Explanation of Solution

Example of dataset

Consider the case where a professor in physics department teaches an electric engineering course.

Even though there is a valid entry in teaches, it is lost in the natural join of instructor, teaches and course, since the instructor’s department name does not match the department name of the course...

Answer 10

b.

Explanation of Solution

Reason for using query

The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

Answer 11

b.

Explanation of Solution

Reason for using query

The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

Answer 12

c.

Explanation of Solution

Reason for using query

In the query,

select * from teaches natural join instructor;

In the above query, some sections are lost if teaches...

Answer 13

c.

Explanation of Solution

Reason for using query

In the query,

select * from teaches natural join instructor;

In the above query, some sections are lost if teaches...

Answer 14

Expert Solution & Answer

Answer 15

Expert Solution & Answer

Answer 16

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Answer 17

Ch. 4 - Prob. 1PE Ch. 4 - Prob. 2PE Ch. 4 - Prob. 3PE Ch. 4 - Prob. 4PE Ch. 4 - Prob. 5PE Ch. 4 - Prob. 6PE Ch. 4 - Prob. 7PE Ch. 4 - Prob. 8PE Ch. 4 - SQL allows a foreign-key dependency to refer to...Ch. 4 - Given the relations a(name, address, title) and...

Explanation of Solution

Explanation of Solution

Reason for using query The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

Explanation of Solution

Reason for using query In the query, select * from teaches natural join instructor; In the above query, some sections are lost if teaches...

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Chapter 4 Solutions

Reason for using query

The query that computes the natural join of instructor, teaches and course is an example for creating tuples in reference relation ...

Reason for using query

In the query,

select * from teaches natural join instructor;

In the above query, some sections are lost if teaches...